This article examines how the urban context, rather than national or regional context, shapes local immigrant integration policies. We draw on the integration experiences of four large European and American cities-Berlin, Amsterdam, New York City, and San Francisco-to develop a basic inductive framework for explaining when and why city officials enact and implement policies that promote immigrant integration. Our framework highlights the importance for cities to have (1) left-leaning governments, (2) immigrants who constitute a large part of the city electorate and are part of local decision-making structures, and (3) an infrastructure of community-based organisations that actively represent immigrants' collective interests in local politics and policy-making. We show that when these three factors exist synergistically, cities are more likely to commit themselves to policies that promote immigrant integration even when the national context is not very hospitable to immigrant rights.